[lttng-ust.git] / liblttng-ust / lttng-bytecode.c

/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * LTTng UST bytecode code.
 */

#define _LGPL_SOURCE
#include <stddef.h>
#include <stdint.h>

#include <urcu/rculist.h>

#include "context-internal.h"
#include "lttng-bytecode.h"
#include "ust-events-internal.h"

static const char *opnames[] = {
	[ BYTECODE_OP_UNKNOWN ] = "UNKNOWN",

	[ BYTECODE_OP_RETURN ] = "RETURN",

	/* binary */
	[ BYTECODE_OP_MUL ] = "MUL",
	[ BYTECODE_OP_DIV ] = "DIV",
	[ BYTECODE_OP_MOD ] = "MOD",
	[ BYTECODE_OP_PLUS ] = "PLUS",
	[ BYTECODE_OP_MINUS ] = "MINUS",
	[ BYTECODE_OP_BIT_RSHIFT ] = "BIT_RSHIFT",
	[ BYTECODE_OP_BIT_LSHIFT ] = "BIT_LSHIFT",
	[ BYTECODE_OP_BIT_AND ] = "BIT_AND",
	[ BYTECODE_OP_BIT_OR ] = "BIT_OR",
	[ BYTECODE_OP_BIT_XOR ] = "BIT_XOR",

	/* binary comparators */
	[ BYTECODE_OP_EQ ] = "EQ",
	[ BYTECODE_OP_NE ] = "NE",
	[ BYTECODE_OP_GT ] = "GT",
	[ BYTECODE_OP_LT ] = "LT",
	[ BYTECODE_OP_GE ] = "GE",
	[ BYTECODE_OP_LE ] = "LE",

	/* string binary comparators */
	[ BYTECODE_OP_EQ_STRING ] = "EQ_STRING",
	[ BYTECODE_OP_NE_STRING ] = "NE_STRING",
	[ BYTECODE_OP_GT_STRING ] = "GT_STRING",
	[ BYTECODE_OP_LT_STRING ] = "LT_STRING",
	[ BYTECODE_OP_GE_STRING ] = "GE_STRING",
	[ BYTECODE_OP_LE_STRING ] = "LE_STRING",

	/* s64 binary comparators */
	[ BYTECODE_OP_EQ_S64 ] = "EQ_S64",
	[ BYTECODE_OP_NE_S64 ] = "NE_S64",
	[ BYTECODE_OP_GT_S64 ] = "GT_S64",
	[ BYTECODE_OP_LT_S64 ] = "LT_S64",
	[ BYTECODE_OP_GE_S64 ] = "GE_S64",
	[ BYTECODE_OP_LE_S64 ] = "LE_S64",

	/* double binary comparators */
	[ BYTECODE_OP_EQ_DOUBLE ] = "EQ_DOUBLE",
	[ BYTECODE_OP_NE_DOUBLE ] = "NE_DOUBLE",
	[ BYTECODE_OP_GT_DOUBLE ] = "GT_DOUBLE",
	[ BYTECODE_OP_LT_DOUBLE ] = "LT_DOUBLE",
	[ BYTECODE_OP_GE_DOUBLE ] = "GE_DOUBLE",
	[ BYTECODE_OP_LE_DOUBLE ] = "LE_DOUBLE",

	/* Mixed S64-double binary comparators */
	[ BYTECODE_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64",
	[ BYTECODE_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64",
	[ BYTECODE_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64",
	[ BYTECODE_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64",
	[ BYTECODE_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64",
	[ BYTECODE_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64",

	[ BYTECODE_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE",
	[ BYTECODE_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE",
	[ BYTECODE_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE",
	[ BYTECODE_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE",
	[ BYTECODE_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE",
	[ BYTECODE_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE",

	/* unary */
	[ BYTECODE_OP_UNARY_PLUS ] = "UNARY_PLUS",
	[ BYTECODE_OP_UNARY_MINUS ] = "UNARY_MINUS",
	[ BYTECODE_OP_UNARY_NOT ] = "UNARY_NOT",
	[ BYTECODE_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64",
	[ BYTECODE_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64",
	[ BYTECODE_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64",
	[ BYTECODE_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE",
	[ BYTECODE_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE",
	[ BYTECODE_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE",

	/* logical */
	[ BYTECODE_OP_AND ] = "AND",
	[ BYTECODE_OP_OR ] = "OR",

	/* load field ref */
	[ BYTECODE_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF",
	[ BYTECODE_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING",
	[ BYTECODE_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE",
	[ BYTECODE_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64",
	[ BYTECODE_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE",

	/* load from immediate operand */
	[ BYTECODE_OP_LOAD_STRING ] = "LOAD_STRING",
	[ BYTECODE_OP_LOAD_S64 ] = "LOAD_S64",
	[ BYTECODE_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",

	/* cast */
	[ BYTECODE_OP_CAST_TO_S64 ] = "CAST_TO_S64",
	[ BYTECODE_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
	[ BYTECODE_OP_CAST_NOP ] = "CAST_NOP",

	/* get context ref */
	[ BYTECODE_OP_GET_CONTEXT_REF ] = "GET_CONTEXT_REF",
	[ BYTECODE_OP_GET_CONTEXT_REF_STRING ] = "GET_CONTEXT_REF_STRING",
	[ BYTECODE_OP_GET_CONTEXT_REF_S64 ] = "GET_CONTEXT_REF_S64",
	[ BYTECODE_OP_GET_CONTEXT_REF_DOUBLE ] = "GET_CONTEXT_REF_DOUBLE",

	/* load userspace field ref */
	[ BYTECODE_OP_LOAD_FIELD_REF_USER_STRING ] = "LOAD_FIELD_REF_USER_STRING",
	[ BYTECODE_OP_LOAD_FIELD_REF_USER_SEQUENCE ] = "LOAD_FIELD_REF_USER_SEQUENCE",

	/*
	 * load immediate star globbing pattern (literal string)
	 * from immediate.
	 */
	[ BYTECODE_OP_LOAD_STAR_GLOB_STRING ] = "LOAD_STAR_GLOB_STRING",

	/* globbing pattern binary operator: apply to */
	[ BYTECODE_OP_EQ_STAR_GLOB_STRING ] = "EQ_STAR_GLOB_STRING",
	[ BYTECODE_OP_NE_STAR_GLOB_STRING ] = "NE_STAR_GLOB_STRING",

	/*
	 * Instructions for recursive traversal through composed types.
	 */
	[ BYTECODE_OP_GET_CONTEXT_ROOT ] = "GET_CONTEXT_ROOT",
	[ BYTECODE_OP_GET_APP_CONTEXT_ROOT ] = "GET_APP_CONTEXT_ROOT",
	[ BYTECODE_OP_GET_PAYLOAD_ROOT ] = "GET_PAYLOAD_ROOT",

	[ BYTECODE_OP_GET_SYMBOL ] = "GET_SYMBOL",
	[ BYTECODE_OP_GET_SYMBOL_FIELD ] = "GET_SYMBOL_FIELD",
	[ BYTECODE_OP_GET_INDEX_U16 ] = "GET_INDEX_U16",
	[ BYTECODE_OP_GET_INDEX_U64 ] = "GET_INDEX_U64",

	[ BYTECODE_OP_LOAD_FIELD ] = "LOAD_FIELD",
	[ BYTECODE_OP_LOAD_FIELD_S8 ] = "LOAD_FIELD_S8",
	[ BYTECODE_OP_LOAD_FIELD_S16 ] = "LOAD_FIELD_S16",
	[ BYTECODE_OP_LOAD_FIELD_S32 ] = "LOAD_FIELD_S32",
	[ BYTECODE_OP_LOAD_FIELD_S64 ] = "LOAD_FIELD_S64",
	[ BYTECODE_OP_LOAD_FIELD_U8 ] = "LOAD_FIELD_U8",
	[ BYTECODE_OP_LOAD_FIELD_U16 ] = "LOAD_FIELD_U16",
	[ BYTECODE_OP_LOAD_FIELD_U32 ] = "LOAD_FIELD_U32",
	[ BYTECODE_OP_LOAD_FIELD_U64 ] = "LOAD_FIELD_U64",
	[ BYTECODE_OP_LOAD_FIELD_STRING ] = "LOAD_FIELD_STRING",
	[ BYTECODE_OP_LOAD_FIELD_SEQUENCE ] = "LOAD_FIELD_SEQUENCE",
	[ BYTECODE_OP_LOAD_FIELD_DOUBLE ] = "LOAD_FIELD_DOUBLE",

	[ BYTECODE_OP_UNARY_BIT_NOT ] = "UNARY_BIT_NOT",

	[ BYTECODE_OP_RETURN_S64 ] = "RETURN_S64",
};

const char *print_op(enum bytecode_op op)
{
	if (op >= NR_BYTECODE_OPS)
		return "UNKNOWN";
	else
		return opnames[op];
}

static
int apply_field_reloc(const struct lttng_event_desc *event_desc,
		struct bytecode_runtime *runtime,
		uint32_t runtime_len,
		uint32_t reloc_offset,
		const char *field_name,
		enum bytecode_op bytecode_op)
{
	const struct lttng_event_field *fields, *field = NULL;
	unsigned int nr_fields, i;
	struct load_op *op;
	uint32_t field_offset = 0;

	dbg_printf("Apply field reloc: %u %s\n", reloc_offset, field_name);

	/* Lookup event by name */
	if (!event_desc)
		return -EINVAL;
	fields = event_desc->fields;
	if (!fields)
		return -EINVAL;
	nr_fields = event_desc->nr_fields;
	for (i = 0; i < nr_fields; i++) {
		if (fields[i].u.ext.nofilter) {
			continue;
		}
		if (!strcmp(fields[i].name, field_name)) {
			field = &fields[i];
			break;
		}
		/* compute field offset */
		switch (fields[i].type.atype) {
		case atype_integer:
		case atype_enum:
		case atype_enum_nestable:
			field_offset += sizeof(int64_t);
			break;
		case atype_array:
		case atype_array_nestable:
		case atype_sequence:
		case atype_sequence_nestable:
			field_offset += sizeof(unsigned long);
			field_offset += sizeof(void *);
			break;
		case atype_string:
			field_offset += sizeof(void *);
			break;
		case atype_float:
			field_offset += sizeof(double);
			break;
		default:
			return -EINVAL;
		}
	}
	if (!field)
		return -EINVAL;

	/* Check if field offset is too large for 16-bit offset */
	if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
		return -EINVAL;

	/* set type */
	op = (struct load_op *) &runtime->code[reloc_offset];

	switch (bytecode_op) {
	case BYTECODE_OP_LOAD_FIELD_REF:
	{
		struct field_ref *field_ref;

		field_ref = (struct field_ref *) op->data;
		switch (field->type.atype) {
		case atype_integer:
		case atype_enum:
		case atype_enum_nestable:
			op->op = BYTECODE_OP_LOAD_FIELD_REF_S64;
			break;
		case atype_array:
		case atype_array_nestable:
		case atype_sequence:
		case atype_sequence_nestable:
			op->op = BYTECODE_OP_LOAD_FIELD_REF_SEQUENCE;
			break;
		case atype_string:
			op->op = BYTECODE_OP_LOAD_FIELD_REF_STRING;
			break;
		case atype_float:
			op->op = BYTECODE_OP_LOAD_FIELD_REF_DOUBLE;
			break;
		default:
			return -EINVAL;
		}
		/* set offset */
		field_ref->offset = (uint16_t) field_offset;
		break;
	}
	default:
		return -EINVAL;
	}
	return 0;
}

static
int apply_context_reloc(struct bytecode_runtime *runtime,
		uint32_t runtime_len,
		uint32_t reloc_offset,
		const char *context_name,
		enum bytecode_op bytecode_op)
{
	struct load_op *op;
	struct lttng_ctx_field *ctx_field;
	int idx;
	struct lttng_ctx **pctx = runtime->p.pctx;

	dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);

	/* Get context index */
	idx = lttng_get_context_index(*pctx, context_name);
	if (idx < 0) {
		if (lttng_context_is_app(context_name)) {
			int ret;

			ret = lttng_ust_add_app_context_to_ctx_rcu(context_name,
					pctx);
			if (ret)
				return ret;
			idx = lttng_get_context_index(*pctx, context_name);
			if (idx < 0)
				return -ENOENT;
		} else {
			return -ENOENT;
		}
	}
	/* Check if idx is too large for 16-bit offset */
	if (idx > FILTER_BYTECODE_MAX_LEN - 1)
		return -EINVAL;

	/* Get context return type */
	ctx_field = &(*pctx)->fields[idx];
	op = (struct load_op *) &runtime->code[reloc_offset];

	switch (bytecode_op) {
	case BYTECODE_OP_GET_CONTEXT_REF:
	{
		struct field_ref *field_ref;

		field_ref = (struct field_ref *) op->data;
		switch (ctx_field->event_field.type.atype) {
		case atype_integer:
		case atype_enum:
		case atype_enum_nestable:
			op->op = BYTECODE_OP_GET_CONTEXT_REF_S64;
			break;
			/* Sequence and array supported as string */
		case atype_string:
		case atype_array:
		case atype_array_nestable:
		case atype_sequence:
		case atype_sequence_nestable:
			op->op = BYTECODE_OP_GET_CONTEXT_REF_STRING;
			break;
		case atype_float:
			op->op = BYTECODE_OP_GET_CONTEXT_REF_DOUBLE;
			break;
		case atype_dynamic:
			op->op = BYTECODE_OP_GET_CONTEXT_REF;
			break;
		default:
			return -EINVAL;
		}
		/* set offset to context index within channel contexts */
		field_ref->offset = (uint16_t) idx;
		break;
	}
	default:
		return -EINVAL;
	}
	return 0;
}

static
int apply_reloc(const struct lttng_event_desc *event_desc,
		struct bytecode_runtime *runtime,
		uint32_t runtime_len,
		uint32_t reloc_offset,
		const char *name)
{
	struct load_op *op;

	dbg_printf("Apply reloc: %u %s\n", reloc_offset, name);

	/* Ensure that the reloc is within the code */
	if (runtime_len - reloc_offset < sizeof(uint16_t))
		return -EINVAL;

	op = (struct load_op *) &runtime->code[reloc_offset];
	switch (op->op) {
	case BYTECODE_OP_LOAD_FIELD_REF:
		return apply_field_reloc(event_desc, runtime, runtime_len,
			reloc_offset, name, op->op);
	case BYTECODE_OP_GET_CONTEXT_REF:
		return apply_context_reloc(runtime, runtime_len,
			reloc_offset, name, op->op);
	case BYTECODE_OP_GET_SYMBOL:
	case BYTECODE_OP_GET_SYMBOL_FIELD:
		/*
		 * Will be handled by load specialize phase or
		 * dynamically by interpreter.
		 */
		return 0;
	default:
		ERR("Unknown reloc op type %u\n", op->op);
		return -EINVAL;
	}
	return 0;
}

static
int bytecode_is_linked(struct lttng_ust_bytecode_node *bytecode,
		struct cds_list_head *bytecode_runtime_head)
{
	struct lttng_bytecode_runtime *bc_runtime;

	cds_list_for_each_entry(bc_runtime, bytecode_runtime_head, node) {
		if (bc_runtime->bc == bytecode)
			return 1;
	}
	return 0;
}

/*
 * Take a bytecode with reloc table and link it to an event to create a
 * bytecode runtime.
 */
static
int link_bytecode(const struct lttng_event_desc *event_desc,
		struct lttng_ctx **ctx,
		struct lttng_ust_bytecode_node *bytecode,
		struct cds_list_head *insert_loc)
{
	int ret, offset, next_offset;
	struct bytecode_runtime *runtime = NULL;
	size_t runtime_alloc_len;

	if (!bytecode)
		return 0;
	/* Bytecode already linked */
	if (bytecode_is_linked(bytecode, insert_loc))
		return 0;

	dbg_printf("Linking...\n");

	/* We don't need the reloc table in the runtime */
	runtime_alloc_len = sizeof(*runtime) + bytecode->bc.reloc_offset;
	runtime = zmalloc(runtime_alloc_len);
	if (!runtime) {
		ret = -ENOMEM;
		goto alloc_error;
	}
	runtime->p.bc = bytecode;
	runtime->p.pctx = ctx;
	runtime->len = bytecode->bc.reloc_offset;
	/* copy original bytecode */
	memcpy(runtime->code, bytecode->bc.data, runtime->len);
	/*
	 * apply relocs. Those are a uint16_t (offset in bytecode)
	 * followed by a string (field name).
	 */
	for (offset = bytecode->bc.reloc_offset;
			offset < bytecode->bc.len;
			offset = next_offset) {
		uint16_t reloc_offset =
			*(uint16_t *) &bytecode->bc.data[offset];
		const char *name =
			(const char *) &bytecode->bc.data[offset + sizeof(uint16_t)];

		ret = apply_reloc(event_desc, runtime, runtime->len, reloc_offset, name);
		if (ret) {
			goto link_error;
		}
		next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
	}
	/* Validate bytecode */
	ret = lttng_bytecode_validate(runtime);
	if (ret) {
		goto link_error;
	}
	/* Specialize bytecode */
	ret = lttng_bytecode_specialize(event_desc, runtime);
	if (ret) {
		goto link_error;
	}

	switch (bytecode->type) {
	case LTTNG_UST_BYTECODE_NODE_TYPE_FILTER:
		runtime->p.interpreter_funcs.filter = lttng_bytecode_filter_interpret;
		break;
	case LTTNG_UST_BYTECODE_NODE_TYPE_CAPTURE:
		runtime->p.interpreter_funcs.capture = lttng_bytecode_capture_interpret;
		break;
	default:
		abort();
	}

	runtime->p.link_failed = 0;
	cds_list_add_rcu(&runtime->p.node, insert_loc);
	dbg_printf("Linking successful.\n");
	return 0;

link_error:
	switch (bytecode->type) {
	case LTTNG_UST_BYTECODE_NODE_TYPE_FILTER:
		runtime->p.interpreter_funcs.filter = lttng_bytecode_filter_interpret_false;
		break;
	case LTTNG_UST_BYTECODE_NODE_TYPE_CAPTURE:
		runtime->p.interpreter_funcs.capture = lttng_bytecode_capture_interpret_false;
		break;
	default:
		abort();
	}

	runtime->p.link_failed = 1;
	cds_list_add_rcu(&runtime->p.node, insert_loc);
alloc_error:
	dbg_printf("Linking failed.\n");
	return ret;
}

void lttng_bytecode_filter_sync_state(struct lttng_bytecode_runtime *runtime)
{
	struct lttng_ust_bytecode_node *bc = runtime->bc;

	if (!bc->enabler->enabled || runtime->link_failed)
		runtime->interpreter_funcs.filter = lttng_bytecode_filter_interpret_false;
	else
		runtime->interpreter_funcs.filter = lttng_bytecode_filter_interpret;
}

void lttng_bytecode_capture_sync_state(struct lttng_bytecode_runtime *runtime)
{
	struct lttng_ust_bytecode_node *bc = runtime->bc;

	if (!bc->enabler->enabled || runtime->link_failed)
		runtime->interpreter_funcs.capture = lttng_bytecode_capture_interpret_false;
	else
		runtime->interpreter_funcs.capture = lttng_bytecode_capture_interpret;
}

/*
 * Given the lists of bytecode programs of an instance (trigger or event) and
 * of a matching enabler, try to link all the enabler's bytecode programs with
 * the instance.
 *
 * This function is called after we confirmed that name enabler and the
 * instance are name matching (or glob pattern matching).
 */
void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
		struct lttng_ctx **ctx,
		struct cds_list_head *instance_bytecode_head,
		struct cds_list_head *enabler_bytecode_head)
{
	struct lttng_ust_bytecode_node *enabler_bc;
	struct lttng_bytecode_runtime *runtime;

	assert(event_desc);

	/* Go over all the bytecode programs of the enabler. */
	cds_list_for_each_entry(enabler_bc, enabler_bytecode_head, node) {
		int found = 0, ret;
		struct cds_list_head *insert_loc;

		/*
		 * Check if the current enabler bytecode program is already
		 * linked with the instance.
		 */
		cds_list_for_each_entry(runtime, instance_bytecode_head, node) {
			if (runtime->bc == enabler_bc) {
				found = 1;
				break;
			}
		}

		/*
		 * Skip bytecode already linked, go to the next enabler
		 * bytecode program.
		 */
		if (found)
			continue;

		/*
		 * Insert at specified priority (seqnum) in increasing
		 * order. If there already is a bytecode of the same priority,
		 * insert the new bytecode right after it.
		 */
		cds_list_for_each_entry_reverse(runtime,
				instance_bytecode_head, node) {
			if (runtime->bc->bc.seqnum <= enabler_bc->bc.seqnum) {
				/* insert here */
				insert_loc = &runtime->node;
				goto add_within;
			}
		}

		/* Add to head to list */
		insert_loc = instance_bytecode_head;
	add_within:
		dbg_printf("linking bytecode\n");
		ret = link_bytecode(event_desc, ctx, enabler_bc, insert_loc);
		if (ret) {
			dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
		}
	}
}

/*
 * We own the bytecode if we return success.
 */
int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
		struct lttng_ust_bytecode_node *bytecode)
{
	cds_list_add(&bytecode->node, &enabler->filter_bytecode_head);
	return 0;
}

static
void free_filter_runtime(struct cds_list_head *bytecode_runtime_head)
{
	struct bytecode_runtime *runtime, *tmp;

	cds_list_for_each_entry_safe(runtime, tmp, bytecode_runtime_head,
			p.node) {
		free(runtime->data);
		free(runtime);
	}
}

void lttng_free_event_filter_runtime(struct lttng_event *event)
{
	free_filter_runtime(&event->filter_bytecode_runtime_head);
}

void lttng_free_event_notifier_filter_runtime(
		struct lttng_event_notifier *event_notifier)
{
	free_filter_runtime(&event_notifier->filter_bytecode_runtime_head);
}
Commit	Line	Data
	1	/*
	2	* SPDX-License-Identifier: MIT
	3	*
	4	* Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
	6	* LTTng UST bytecode code.
	7	*/
	8
	9	#define _LGPL_SOURCE
	10	#include <stddef.h>
	11	#include <stdint.h>
	12
	13	#include <urcu/rculist.h>
	14
	15	#include "context-internal.h"
	16	#include "lttng-bytecode.h"
	17	#include "ust-events-internal.h"
	18
	19	static const char *opnames[] = {
	20	[ BYTECODE_OP_UNKNOWN ] = "UNKNOWN",
	21
	22	[ BYTECODE_OP_RETURN ] = "RETURN",
	23
	24	/* binary */
	25	[ BYTECODE_OP_MUL ] = "MUL",
	26	[ BYTECODE_OP_DIV ] = "DIV",
	27	[ BYTECODE_OP_MOD ] = "MOD",
	28	[ BYTECODE_OP_PLUS ] = "PLUS",
	29	[ BYTECODE_OP_MINUS ] = "MINUS",
	30	[ BYTECODE_OP_BIT_RSHIFT ] = "BIT_RSHIFT",
	31	[ BYTECODE_OP_BIT_LSHIFT ] = "BIT_LSHIFT",
	32	[ BYTECODE_OP_BIT_AND ] = "BIT_AND",
	33	[ BYTECODE_OP_BIT_OR ] = "BIT_OR",
	34	[ BYTECODE_OP_BIT_XOR ] = "BIT_XOR",
	35
	36	/* binary comparators */
	37	[ BYTECODE_OP_EQ ] = "EQ",
	38	[ BYTECODE_OP_NE ] = "NE",
	39	[ BYTECODE_OP_GT ] = "GT",
	40	[ BYTECODE_OP_LT ] = "LT",
	41	[ BYTECODE_OP_GE ] = "GE",
	42	[ BYTECODE_OP_LE ] = "LE",
	43
	44	/* string binary comparators */
	45	[ BYTECODE_OP_EQ_STRING ] = "EQ_STRING",
	46	[ BYTECODE_OP_NE_STRING ] = "NE_STRING",
	47	[ BYTECODE_OP_GT_STRING ] = "GT_STRING",
	48	[ BYTECODE_OP_LT_STRING ] = "LT_STRING",
	49	[ BYTECODE_OP_GE_STRING ] = "GE_STRING",
	50	[ BYTECODE_OP_LE_STRING ] = "LE_STRING",
	51
	52	/* s64 binary comparators */
	53	[ BYTECODE_OP_EQ_S64 ] = "EQ_S64",
	54	[ BYTECODE_OP_NE_S64 ] = "NE_S64",
	55	[ BYTECODE_OP_GT_S64 ] = "GT_S64",
	56	[ BYTECODE_OP_LT_S64 ] = "LT_S64",
	57	[ BYTECODE_OP_GE_S64 ] = "GE_S64",
	58	[ BYTECODE_OP_LE_S64 ] = "LE_S64",
	59
	60	/* double binary comparators */
	61	[ BYTECODE_OP_EQ_DOUBLE ] = "EQ_DOUBLE",
	62	[ BYTECODE_OP_NE_DOUBLE ] = "NE_DOUBLE",
	63	[ BYTECODE_OP_GT_DOUBLE ] = "GT_DOUBLE",
	64	[ BYTECODE_OP_LT_DOUBLE ] = "LT_DOUBLE",
	65	[ BYTECODE_OP_GE_DOUBLE ] = "GE_DOUBLE",
	66	[ BYTECODE_OP_LE_DOUBLE ] = "LE_DOUBLE",
	67
	68	/* Mixed S64-double binary comparators */
	69	[ BYTECODE_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64",
	70	[ BYTECODE_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64",
	71	[ BYTECODE_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64",
	72	[ BYTECODE_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64",
	73	[ BYTECODE_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64",
	74	[ BYTECODE_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64",
	75
	76	[ BYTECODE_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE",
	77	[ BYTECODE_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE",
	78	[ BYTECODE_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE",
	79	[ BYTECODE_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE",
	80	[ BYTECODE_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE",
	81	[ BYTECODE_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE",
	82
	83	/* unary */
	84	[ BYTECODE_OP_UNARY_PLUS ] = "UNARY_PLUS",
	85	[ BYTECODE_OP_UNARY_MINUS ] = "UNARY_MINUS",
	86	[ BYTECODE_OP_UNARY_NOT ] = "UNARY_NOT",
	87	[ BYTECODE_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64",
	88	[ BYTECODE_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64",
	89	[ BYTECODE_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64",
	90	[ BYTECODE_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE",
	91	[ BYTECODE_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE",
	92	[ BYTECODE_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE",
	93
	94	/* logical */
	95	[ BYTECODE_OP_AND ] = "AND",
	96	[ BYTECODE_OP_OR ] = "OR",
	97
	98	/* load field ref */
	99	[ BYTECODE_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF",
	100	[ BYTECODE_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING",
	101	[ BYTECODE_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE",
	102	[ BYTECODE_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64",
	103	[ BYTECODE_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE",
	104
	105	/* load from immediate operand */
	106	[ BYTECODE_OP_LOAD_STRING ] = "LOAD_STRING",
	107	[ BYTECODE_OP_LOAD_S64 ] = "LOAD_S64",
	108	[ BYTECODE_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",
	109
	110	/* cast */
	111	[ BYTECODE_OP_CAST_TO_S64 ] = "CAST_TO_S64",
	112	[ BYTECODE_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
	113	[ BYTECODE_OP_CAST_NOP ] = "CAST_NOP",
	114
	115	/* get context ref */
	116	[ BYTECODE_OP_GET_CONTEXT_REF ] = "GET_CONTEXT_REF",
	117	[ BYTECODE_OP_GET_CONTEXT_REF_STRING ] = "GET_CONTEXT_REF_STRING",
	118	[ BYTECODE_OP_GET_CONTEXT_REF_S64 ] = "GET_CONTEXT_REF_S64",
	119	[ BYTECODE_OP_GET_CONTEXT_REF_DOUBLE ] = "GET_CONTEXT_REF_DOUBLE",
	120
	121	/* load userspace field ref */
	122	[ BYTECODE_OP_LOAD_FIELD_REF_USER_STRING ] = "LOAD_FIELD_REF_USER_STRING",
	123	[ BYTECODE_OP_LOAD_FIELD_REF_USER_SEQUENCE ] = "LOAD_FIELD_REF_USER_SEQUENCE",
	124
	125	/*
	126	* load immediate star globbing pattern (literal string)
	127	* from immediate.
	128	*/
	129	[ BYTECODE_OP_LOAD_STAR_GLOB_STRING ] = "LOAD_STAR_GLOB_STRING",
	130
	131	/* globbing pattern binary operator: apply to */
	132	[ BYTECODE_OP_EQ_STAR_GLOB_STRING ] = "EQ_STAR_GLOB_STRING",
	133	[ BYTECODE_OP_NE_STAR_GLOB_STRING ] = "NE_STAR_GLOB_STRING",
	134
	135	/*
	136	* Instructions for recursive traversal through composed types.
	137	*/
	138	[ BYTECODE_OP_GET_CONTEXT_ROOT ] = "GET_CONTEXT_ROOT",
	139	[ BYTECODE_OP_GET_APP_CONTEXT_ROOT ] = "GET_APP_CONTEXT_ROOT",
	140	[ BYTECODE_OP_GET_PAYLOAD_ROOT ] = "GET_PAYLOAD_ROOT",
	141
	142	[ BYTECODE_OP_GET_SYMBOL ] = "GET_SYMBOL",
	143	[ BYTECODE_OP_GET_SYMBOL_FIELD ] = "GET_SYMBOL_FIELD",
	144	[ BYTECODE_OP_GET_INDEX_U16 ] = "GET_INDEX_U16",
	145	[ BYTECODE_OP_GET_INDEX_U64 ] = "GET_INDEX_U64",
	146
	147	[ BYTECODE_OP_LOAD_FIELD ] = "LOAD_FIELD",
	148	[ BYTECODE_OP_LOAD_FIELD_S8 ] = "LOAD_FIELD_S8",
	149	[ BYTECODE_OP_LOAD_FIELD_S16 ] = "LOAD_FIELD_S16",
	150	[ BYTECODE_OP_LOAD_FIELD_S32 ] = "LOAD_FIELD_S32",
	151	[ BYTECODE_OP_LOAD_FIELD_S64 ] = "LOAD_FIELD_S64",
	152	[ BYTECODE_OP_LOAD_FIELD_U8 ] = "LOAD_FIELD_U8",
	153	[ BYTECODE_OP_LOAD_FIELD_U16 ] = "LOAD_FIELD_U16",
	154	[ BYTECODE_OP_LOAD_FIELD_U32 ] = "LOAD_FIELD_U32",
	155	[ BYTECODE_OP_LOAD_FIELD_U64 ] = "LOAD_FIELD_U64",
	156	[ BYTECODE_OP_LOAD_FIELD_STRING ] = "LOAD_FIELD_STRING",
	157	[ BYTECODE_OP_LOAD_FIELD_SEQUENCE ] = "LOAD_FIELD_SEQUENCE",
	158	[ BYTECODE_OP_LOAD_FIELD_DOUBLE ] = "LOAD_FIELD_DOUBLE",
	159
	160	[ BYTECODE_OP_UNARY_BIT_NOT ] = "UNARY_BIT_NOT",
	161
	162	[ BYTECODE_OP_RETURN_S64 ] = "RETURN_S64",
	163	};
	164
	165	const char *print_op(enum bytecode_op op)
	166	{
	167	if (op >= NR_BYTECODE_OPS)
	168	return "UNKNOWN";
	169	else
	170	return opnames[op];
	171	}
	172
	173	static
	174	int apply_field_reloc(const struct lttng_event_desc *event_desc,
	175	struct bytecode_runtime *runtime,
	176	uint32_t runtime_len,
	177	uint32_t reloc_offset,
	178	const char *field_name,
	179	enum bytecode_op bytecode_op)
	180	{
	181	const struct lttng_event_field fields, field = NULL;
	182	unsigned int nr_fields, i;
	183	struct load_op *op;
	184	uint32_t field_offset = 0;
	185
	186	dbg_printf("Apply field reloc: %u %s\n", reloc_offset, field_name);
	187
	188	/* Lookup event by name */
	189	if (!event_desc)
	190	return -EINVAL;
	191	fields = event_desc->fields;
	192	if (!fields)
	193	return -EINVAL;
	194	nr_fields = event_desc->nr_fields;
	195	for (i = 0; i < nr_fields; i++) {
	196	if (fields[i].u.ext.nofilter) {
	197	continue;
	198	}
	199	if (!strcmp(fields[i].name, field_name)) {
	200	field = &fields[i];
	201	break;
	202	}
	203	/* compute field offset */
	204	switch (fields[i].type.atype) {
	205	case atype_integer:
	206	case atype_enum:
	207	case atype_enum_nestable:
	208	field_offset += sizeof(int64_t);
	209	break;
	210	case atype_array:
	211	case atype_array_nestable:
	212	case atype_sequence:
	213	case atype_sequence_nestable:
	214	field_offset += sizeof(unsigned long);
	215	field_offset += sizeof(void *);
	216	break;
	217	case atype_string:
	218	field_offset += sizeof(void *);
	219	break;
	220	case atype_float:
	221	field_offset += sizeof(double);
	222	break;
	223	default:
	224	return -EINVAL;
	225	}
	226	}
	227	if (!field)
	228	return -EINVAL;
	229
	230	/* Check if field offset is too large for 16-bit offset */
	231	if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
	232	return -EINVAL;
	233
	234	/* set type */
	235	op = (struct load_op *) &runtime->code[reloc_offset];
	236
	237	switch (bytecode_op) {
	238	case BYTECODE_OP_LOAD_FIELD_REF:
	239	{
	240	struct field_ref *field_ref;
	241
	242	field_ref = (struct field_ref *) op->data;
	243	switch (field->type.atype) {
	244	case atype_integer:
	245	case atype_enum:
	246	case atype_enum_nestable:
	247	op->op = BYTECODE_OP_LOAD_FIELD_REF_S64;
	248	break;
	249	case atype_array:
	250	case atype_array_nestable:
	251	case atype_sequence:
	252	case atype_sequence_nestable:
	253	op->op = BYTECODE_OP_LOAD_FIELD_REF_SEQUENCE;
	254	break;
	255	case atype_string:
	256	op->op = BYTECODE_OP_LOAD_FIELD_REF_STRING;
	257	break;
	258	case atype_float:
	259	op->op = BYTECODE_OP_LOAD_FIELD_REF_DOUBLE;
	260	break;
	261	default:
	262	return -EINVAL;
	263	}
	264	/* set offset */
	265	field_ref->offset = (uint16_t) field_offset;
	266	break;
	267	}
	268	default:
	269	return -EINVAL;
	270	}
	271	return 0;
	272	}
	273
	274	static
	275	int apply_context_reloc(struct bytecode_runtime *runtime,
	276	uint32_t runtime_len,
	277	uint32_t reloc_offset,
	278	const char *context_name,
	279	enum bytecode_op bytecode_op)
	280	{
	281	struct load_op *op;
	282	struct lttng_ctx_field *ctx_field;
	283	int idx;
	284	struct lttng_ctx **pctx = runtime->p.pctx;
	285
	286	dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);
	287
	288	/* Get context index */
	289	idx = lttng_get_context_index(*pctx, context_name);
	290	if (idx < 0) {
	291	if (lttng_context_is_app(context_name)) {
	292	int ret;
	293
	294	ret = lttng_ust_add_app_context_to_ctx_rcu(context_name,
	295	pctx);
	296	if (ret)
	297	return ret;
	298	idx = lttng_get_context_index(*pctx, context_name);
	299	if (idx < 0)
	300	return -ENOENT;
	301	} else {
	302	return -ENOENT;
	303	}
	304	}
	305	/* Check if idx is too large for 16-bit offset */
	306	if (idx > FILTER_BYTECODE_MAX_LEN - 1)
	307	return -EINVAL;
	308
	309	/* Get context return type */
	310	ctx_field = &(*pctx)->fields[idx];
	311	op = (struct load_op *) &runtime->code[reloc_offset];
	312
	313	switch (bytecode_op) {
	314	case BYTECODE_OP_GET_CONTEXT_REF:
	315	{
	316	struct field_ref *field_ref;
	317
	318	field_ref = (struct field_ref *) op->data;
	319	switch (ctx_field->event_field.type.atype) {
	320	case atype_integer:
	321	case atype_enum:
	322	case atype_enum_nestable:
	323	op->op = BYTECODE_OP_GET_CONTEXT_REF_S64;
	324	break;
	325	/* Sequence and array supported as string */
	326	case atype_string:
	327	case atype_array:
	328	case atype_array_nestable:
	329	case atype_sequence:
	330	case atype_sequence_nestable:
	331	op->op = BYTECODE_OP_GET_CONTEXT_REF_STRING;
	332	break;
	333	case atype_float:
	334	op->op = BYTECODE_OP_GET_CONTEXT_REF_DOUBLE;
	335	break;
	336	case atype_dynamic:
	337	op->op = BYTECODE_OP_GET_CONTEXT_REF;
	338	break;
	339	default:
	340	return -EINVAL;
	341	}
	342	/* set offset to context index within channel contexts */
	343	field_ref->offset = (uint16_t) idx;
	344	break;
	345	}
	346	default:
	347	return -EINVAL;
	348	}
	349	return 0;
	350	}
	351
	352	static
	353	int apply_reloc(const struct lttng_event_desc *event_desc,
	354	struct bytecode_runtime *runtime,
	355	uint32_t runtime_len,
	356	uint32_t reloc_offset,
	357	const char *name)
	358	{
	359	struct load_op *op;
	360
	361	dbg_printf("Apply reloc: %u %s\n", reloc_offset, name);
	362
	363	/* Ensure that the reloc is within the code */
	364	if (runtime_len - reloc_offset < sizeof(uint16_t))
	365	return -EINVAL;
	366
	367	op = (struct load_op *) &runtime->code[reloc_offset];
	368	switch (op->op) {
	369	case BYTECODE_OP_LOAD_FIELD_REF:
	370	return apply_field_reloc(event_desc, runtime, runtime_len,
	371	reloc_offset, name, op->op);
	372	case BYTECODE_OP_GET_CONTEXT_REF:
	373	return apply_context_reloc(runtime, runtime_len,
	374	reloc_offset, name, op->op);
	375	case BYTECODE_OP_GET_SYMBOL:
	376	case BYTECODE_OP_GET_SYMBOL_FIELD:
	377	/*
	378	* Will be handled by load specialize phase or
	379	* dynamically by interpreter.
	380	*/
	381	return 0;
	382	default:
	383	ERR("Unknown reloc op type %u\n", op->op);
	384	return -EINVAL;
	385	}
	386	return 0;
	387	}
	388
	389	static
	390	int bytecode_is_linked(struct lttng_ust_bytecode_node *bytecode,
	391	struct cds_list_head *bytecode_runtime_head)
	392	{
	393	struct lttng_bytecode_runtime *bc_runtime;
	394
	395	cds_list_for_each_entry(bc_runtime, bytecode_runtime_head, node) {
	396	if (bc_runtime->bc == bytecode)
	397	return 1;
	398	}
	399	return 0;
	400	}
	401
	402	/*
	403	* Take a bytecode with reloc table and link it to an event to create a
	404	* bytecode runtime.
	405	*/
	406	static
	407	int link_bytecode(const struct lttng_event_desc *event_desc,
	408	struct lttng_ctx **ctx,
	409	struct lttng_ust_bytecode_node *bytecode,
	410	struct cds_list_head *insert_loc)
	411	{
	412	int ret, offset, next_offset;
	413	struct bytecode_runtime *runtime = NULL;
	414	size_t runtime_alloc_len;
	415
	416	if (!bytecode)
	417	return 0;
	418	/* Bytecode already linked */
	419	if (bytecode_is_linked(bytecode, insert_loc))
	420	return 0;
	421
	422	dbg_printf("Linking...\n");
	423
	424	/* We don't need the reloc table in the runtime */
	425	runtime_alloc_len = sizeof(*runtime) + bytecode->bc.reloc_offset;
	426	runtime = zmalloc(runtime_alloc_len);
	427	if (!runtime) {
	428	ret = -ENOMEM;
	429	goto alloc_error;
	430	}
	431	runtime->p.bc = bytecode;
	432	runtime->p.pctx = ctx;
	433	runtime->len = bytecode->bc.reloc_offset;
	434	/* copy original bytecode */
	435	memcpy(runtime->code, bytecode->bc.data, runtime->len);
	436	/*
	437	* apply relocs. Those are a uint16_t (offset in bytecode)
	438	* followed by a string (field name).
	439	*/
	440	for (offset = bytecode->bc.reloc_offset;
	441	offset < bytecode->bc.len;
	442	offset = next_offset) {
	443	uint16_t reloc_offset =
	444	(uint16_t ) &bytecode->bc.data[offset];
	445	const char *name =
	446	(const char *) &bytecode->bc.data[offset + sizeof(uint16_t)];
	447
	448	ret = apply_reloc(event_desc, runtime, runtime->len, reloc_offset, name);
	449	if (ret) {
	450	goto link_error;
	451	}
	452	next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
	453	}
	454	/* Validate bytecode */
	455	ret = lttng_bytecode_validate(runtime);
	456	if (ret) {
	457	goto link_error;
	458	}
	459	/* Specialize bytecode */
	460	ret = lttng_bytecode_specialize(event_desc, runtime);
	461	if (ret) {
	462	goto link_error;
	463	}
	464
	465	switch (bytecode->type) {
	466	case LTTNG_UST_BYTECODE_NODE_TYPE_FILTER:
	467	runtime->p.interpreter_funcs.filter = lttng_bytecode_filter_interpret;
	468	break;
	469	case LTTNG_UST_BYTECODE_NODE_TYPE_CAPTURE:
	470	runtime->p.interpreter_funcs.capture = lttng_bytecode_capture_interpret;
	471	break;
	472	default:
	473	abort();
	474	}
	475
	476	runtime->p.link_failed = 0;
	477	cds_list_add_rcu(&runtime->p.node, insert_loc);
	478	dbg_printf("Linking successful.\n");
	479	return 0;
	480
	481	link_error:
	482	switch (bytecode->type) {
	483	case LTTNG_UST_BYTECODE_NODE_TYPE_FILTER:
	484	runtime->p.interpreter_funcs.filter = lttng_bytecode_filter_interpret_false;
	485	break;
	486	case LTTNG_UST_BYTECODE_NODE_TYPE_CAPTURE:
	487	runtime->p.interpreter_funcs.capture = lttng_bytecode_capture_interpret_false;
	488	break;
	489	default:
	490	abort();
	491	}
	492
	493	runtime->p.link_failed = 1;
	494	cds_list_add_rcu(&runtime->p.node, insert_loc);
	495	alloc_error:
	496	dbg_printf("Linking failed.\n");
	497	return ret;
	498	}
	499
	500	void lttng_bytecode_filter_sync_state(struct lttng_bytecode_runtime *runtime)
	501	{
	502	struct lttng_ust_bytecode_node *bc = runtime->bc;
	503
	504	if (!bc->enabler->enabled \|\| runtime->link_failed)
	505	runtime->interpreter_funcs.filter = lttng_bytecode_filter_interpret_false;
	506	else
	507	runtime->interpreter_funcs.filter = lttng_bytecode_filter_interpret;
	508	}
	509
	510	void lttng_bytecode_capture_sync_state(struct lttng_bytecode_runtime *runtime)
	511	{
	512	struct lttng_ust_bytecode_node *bc = runtime->bc;
	513
	514	if (!bc->enabler->enabled \|\| runtime->link_failed)
	515	runtime->interpreter_funcs.capture = lttng_bytecode_capture_interpret_false;
	516	else
	517	runtime->interpreter_funcs.capture = lttng_bytecode_capture_interpret;
	518	}
	519
	520	/*
	521	* Given the lists of bytecode programs of an instance (trigger or event) and
	522	* of a matching enabler, try to link all the enabler's bytecode programs with
	523	* the instance.
	524	*
	525	* This function is called after we confirmed that name enabler and the
	526	* instance are name matching (or glob pattern matching).
	527	*/
	528	void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
	529	struct lttng_ctx **ctx,
	530	struct cds_list_head *instance_bytecode_head,
	531	struct cds_list_head *enabler_bytecode_head)
	532	{
	533	struct lttng_ust_bytecode_node *enabler_bc;
	534	struct lttng_bytecode_runtime *runtime;
	535
	536	assert(event_desc);
	537
	538	/* Go over all the bytecode programs of the enabler. */
	539	cds_list_for_each_entry(enabler_bc, enabler_bytecode_head, node) {
	540	int found = 0, ret;
	541	struct cds_list_head *insert_loc;
	542
	543	/*
	544	* Check if the current enabler bytecode program is already
	545	* linked with the instance.
	546	*/
	547	cds_list_for_each_entry(runtime, instance_bytecode_head, node) {
	548	if (runtime->bc == enabler_bc) {
	549	found = 1;
	550	break;
	551	}
	552	}
	553
	554	/*
	555	* Skip bytecode already linked, go to the next enabler
	556	* bytecode program.
	557	*/
	558	if (found)
	559	continue;
	560
	561	/*
	562	* Insert at specified priority (seqnum) in increasing
	563	* order. If there already is a bytecode of the same priority,
	564	* insert the new bytecode right after it.
	565	*/
	566	cds_list_for_each_entry_reverse(runtime,
	567	instance_bytecode_head, node) {
	568	if (runtime->bc->bc.seqnum <= enabler_bc->bc.seqnum) {
	569	/* insert here */
	570	insert_loc = &runtime->node;
	571	goto add_within;
	572	}
	573	}
	574
	575	/* Add to head to list */
	576	insert_loc = instance_bytecode_head;
	577	add_within:
	578	dbg_printf("linking bytecode\n");
	579	ret = link_bytecode(event_desc, ctx, enabler_bc, insert_loc);
	580	if (ret) {
	581	dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
	582	}
	583	}
	584	}
	585
	586	/*
	587	* We own the bytecode if we return success.
	588	*/
	589	int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
	590	struct lttng_ust_bytecode_node *bytecode)
	591	{
	592	cds_list_add(&bytecode->node, &enabler->filter_bytecode_head);
	593	return 0;
	594	}
	595
	596	static
	597	void free_filter_runtime(struct cds_list_head *bytecode_runtime_head)
	598	{
	599	struct bytecode_runtime runtime, tmp;
	600
	601	cds_list_for_each_entry_safe(runtime, tmp, bytecode_runtime_head,
	602	p.node) {
	603	free(runtime->data);
	604	free(runtime);
	605	}
	606	}
	607
	608	void lttng_free_event_filter_runtime(struct lttng_event *event)
	609	{
	610	free_filter_runtime(&event->filter_bytecode_runtime_head);
	611	}
	612
	613	void lttng_free_event_notifier_filter_runtime(
	614	struct lttng_event_notifier *event_notifier)
	615	{
	616	free_filter_runtime(&event_notifier->filter_bytecode_runtime_head);
	617	}